diff options
| author | Mikulas Patocka <mpatocka@redhat.com> | 2014-10-01 13:29:48 -0400 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2014-11-13 19:02:20 +0100 |
| commit | de91001eafdb327475a4034b97b1871170d1f0ce (patch) | |
| tree | 9d52269709ae03f59285e48175e6ba8261b23eee /drivers/md | |
| parent | 15188b0745439aa1f686e6eb55cacabbe2ea0244 (diff) | |
dm bufio: when done scanning return from __scan immediately
commit 0e825862f3c04cee40e25f55680333728a4ffa9b upstream.
When __scan frees the required number of buffer entries that the
shrinker requested (nr_to_scan becomes zero) it must return. Before
this fix the __scan code exited only the inner loop and continued in the
outer loop -- which could result in reduced performance due to extra
buffers being freed (e.g. unnecessarily evicted thinp metadata needing
to be synchronously re-read into bufio's cache).
Also, move dm_bufio_cond_resched to __scan's inner loop, so that
iterating the bufio client's lru lists doesn't result in scheduling
latency.
Reported-by: Joe Thornber <thornber@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/dm-bufio.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c index bb8d23d55c4a..a42efc7f69ed 100644 --- a/drivers/md/dm-bufio.c +++ b/drivers/md/dm-bufio.c @@ -1456,9 +1456,9 @@ static long __scan(struct dm_bufio_client *c, unsigned long nr_to_scan, list_for_each_entry_safe_reverse(b, tmp, &c->lru[l], lru_list) { freed += __cleanup_old_buffer(b, gfp_mask, 0); if (!--nr_to_scan) - break; + return freed; + dm_bufio_cond_resched(); } - dm_bufio_cond_resched(); } return freed; } |